JPH0229375Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a pulse combustion device, specifically, a gas distributor connected to a fuel gas supply path having a valve mechanism for preventing backflow of explosion combustion gas from an explosion combustion chamber. A combustion air supply path is disposed upstream of the combustion chamber, and is provided upstream of the gas distributor via a valve mechanism for preventing backflow of explosion combustion gas from the explosion combustion chamber. connected in series and downstream of the explosion combustion chamber,
A suction is generated based on the exhaust dynamic inertia of the combustion gas after the explosive combustion of the gas-air mixture in the explosion combustion chamber, by providing an exhaust passage that discharges the explosive combustion gas from the combustion chamber by its explosive force. By using force to mix fuel gas and combustion air into the combustion chamber and causing a portion of the exhaust combustion gas to flow back into the combustion chamber from the exhaust path, the heat retained in the backflow combustion gas is released. The present invention relates to a pulse combustion device configured to continuously repeat an explosive combustion cycle in which a gas-air mixture is explosively burned.

Such pulse combustion equipment does not require energy for supplying combustion air or ignition other than when starting up, allowing for energy-saving operation.Also, since it is capable of high-load combustion, the equipment itself is compact considering its capacity. In addition, since the exhaust pressure of the combustion gas is high due to the explosive combustion mode, high-speed exhaust is possible even though the exhaust path is configured to be very narrow. Therefore, for example, the exhaust path can be configured with a thin tail pipe. At the same time, extremely high heating efficiency can be obtained when used as an immersion pipe for heating fluids, and furthermore, a part of the combustion gas flows back into the combustion chamber from the exhaust passage just before explosive combustion, resulting in so-called The exhaust gas recirculation combustion mode appears naturally, resulting in low
It has various advantages, including the ability to burn NOx.

However, various problems still remain in putting such a pulse combustion device into practical use. As one of them, this pulse combustion device is
The turndown ratio (ratio between the minimum combustion amount and the maximum combustion amount) is very small (usually around 1:1.1 to 1:2) compared to normal combustion equipment, and therefore the adjustable range of combustion intensity is extremely narrow. It had the disadvantage of being small, which was inconvenient in terms of practicality.

In other words, in the conventional pulse combustion device, as combustion gas is exhausted from the exhaust passage 09 after explosive combustion in the combustion chamber 01, gas is Gas outlet 05B of distributor 05...
The fuel gas is sucked into the combustion chamber 01 through the air passage passage 05A of the backflow prevention valve mechanism 04 and the air passage passage 05A of the gas distributor 05.
Since each tube was formed into a straight tube shape, the turndown ratio was low.

More specifically, in the pulse combustion device, combustion air is sucked in from the air passage 05A by reducing the pressure in the combustion chamber 01, and by flowing combustion air in the air passage 05A, from the gas jet port 05B. Since fuel gas is inhaled, there is no air passage path.
If the diameter of 5A is increased to increase the intake amount of combustion air, the flow velocity of combustion air in the air passage 05A becomes small, making it impossible to increase the intake amount of fuel gas sufficiently; If the diameter of the air passage 05A is made small so that the intake amount of fuel gas can be sufficiently increased, the pressure drop of the air passage 05A will become large, making it impossible to increase the intake amount of combustion air sufficiently. As a result, the maximum combustion amount could not be increased much.

In addition, in the straight pipe-shaped air passage 05A, the mixing of fuel gas and combustion air became insufficient as the amount of fuel gas intake decreased, and the minimum combustion amount could not be reduced much, resulting in turndown. The ratio was getting smaller.

The purpose of the present invention is to achieve a very simple modification by simply changing the shape of the combustion air passage.
The object of the present invention is to make it possible to sufficiently increase the turndown ratio in a pulse combustion device.

The characteristic configuration of the present invention is that each of the numerous combustion air passages formed in the gas distributor for mixing combustion air with fuel gas from the fuel gas supply passage and supplying the mixture to the combustion chamber is connected to the inlet side. The part has a tapered shape in which the inner diameter changes continuously so that the diameter becomes smaller towards the downstream side, and the outlet part has a tapered shape in which the inner diameter changes continuously so that the diameter becomes larger towards the downstream side. The fuel gas outlet from the fuel gas supply path is connected to the vicinity of the minimum diameter portion of each of the passage paths, and its effects are as follows.

In other words, if the combustion air passage is formed by a tapered inlet side part whose inner diameter changes continuously and a tapered outlet side part, the inlet and outlet can be made sufficiently large, and the minimum diameter part can be made large enough. It becomes possible to make the suction speed of the combustion air at the minimum diameter portion sufficiently large while minimizing the pressure drop to the suction of the combustion air.

Therefore, by connecting the fuel gas nozzle near the smallest diameter part of the combustion air passage, it is possible to reduce the intake amount of combustion air due to the pressure reduction in the combustion chamber and the flow of combustion air. By sufficiently increasing both the intake amounts of fuel gas, the maximum combustion amount can be sufficiently increased.

In addition, since the combustion air is flowed from the tapered inlet side part to the tapered outlet side part at a sufficiently increased speed due to the effect of the minimum diameter part, combustion within the tapered outlet side part is carried out. The flow turbulence of the combustion air can be made sufficiently strong, and even if the intake amount of fuel gas is small, the fuel gas and combustion air can be sufficiently mixed at the outlet side and supplied to the combustion chamber, resulting in explosive combustion in pulse combustion equipment. Therefore, the minimum combustion amount can be sufficiently reduced.

As a result, due to the mutual effect of a sufficient increase in the maximum combustion amount and a sufficient decrease in the minimum combustion amount, the turndown ratio of the pulse combustion device can be extremely large, for example, 1:5, which is suitable for applications with large heating load fluctuations. It is now possible to provide a convenient pulse combustion device.

Hereinafter, embodiments of the present invention will be described based on the drawings.

As shown in FIG. 1, a combustion air supply path 3 equipped with an electric fan 2 is provided upstream of an explosion combustion chamber 1 having a starting spark plug 10 to prevent the backflow of explosion combustion gas from the combustion chamber 1. A fuel gas distributor 5 is provided immediately downstream of the valve mechanism 4 for preventing backflow, and a fuel gas distributor 5 is connected to the valve mechanism 4 called an air flapper for preventing combustion. A fuel gas supply path 8 having a gas flow rate control valve 7 for adjusting the amount of combustion via a valve mechanism 6 called a gas flapper for preventing backflow of explosive combustion gas from the chamber 1.
On the downstream side of the explosion combustion chamber 1, a straight tail pipe forming an exhaust passage 9 through which the explosive combustion gas is discharged from the combustion chamber 1 by its explosive force is installed in series. A pulse combustion device is configured.

In the gas distributor 5, each of the numerous combustion air passages 5A has a tapered shape in which the inner diameter continuously changes such that the inlet side portion becomes smaller in diameter toward the downstream side, and the outlet side portion is tapered. The fuel gas jet ports 5B from the fuel gas supply path 8 are connected to the vicinity of the minimum diameter portion of each passageway 5A. However, it is configured so that the maximum intake amount of combustion air and fuel gas can be increased, and even if the intake amount of fuel gas is small, the fuel gas and combustion air can be sufficiently mixed.

As shown in FIG. 2, the backflow prevention valve mechanism 4 for the combustion air supply path 3 has a plurality of ventilation holes 4a arranged in parallel in a circular shape on a disc-shaped valve seat 4A.
On the other hand, a ring-shaped catch seat 4 having a central ventilation hole 4c
A plurality of ventilation holes 4b are provided around the entire circumference of B...
are arranged in parallel, and a large number of bolt/nut-shaped connecting members 4C
The catch seat 4B is integrally connected to the valve seat 4A with an appropriate distance separated therefrom, and the valve seat 4A and the catch seat 4B are
A ring-shaped sliding valve body 4D is inserted between the connecting member 4C.
It is positioned in the radial direction using ......, and when the combustion chamber 1 becomes positive pressure due to explosive combustion, air flows from the central ventilation hole 4c and peripheral ventilation hole 4b ... of the catch seat 4B. Pressing the valve body 4D against the valve seat 4A with the pressing force acting on the valve body 4D to close the valve mechanism 4;
Conversely, if combustion chamber 1 becomes negative pressure immediately after explosive combustion,
Central ventilation hole 4c and peripheral ventilation hole 4b of catch seat 4B
The valve mechanism 4 is configured to be opened by pressing the valve body 4D against the seat 4B by the suction force acting from the valve body 4D.
Then, a heat-resistant and pressure-resistant disk 4E equipped with a central ventilation hole 4d is opposed to the rod-shaped connecting member with its blind portion 4e covering all of the ventilation holes 4b of the seat 4B. 4C..., to suppress the heating of the valve body 4D due to radiant heat transfer from the combustion chamber 1, and also to suppress the heating of the valve body 4D from the combustion chamber 1 to the valve body 4D during explosive combustion.
It is constructed to relieve the enormous dynamic pressure applied to D. In addition, the ventilation hole 4a of the valve seat 4A... and the catch seat 4B
The valve body 4D can be protected even more effectively by combining the configuration in which the ventilation holes 4b are arranged out of phase in the circumferential direction so as not to face each other.

Next, the operation of the pulse combustion device will be explained.

At startup, the electric fan 2 is operated to supply fuel gas and combustion air to the combustion chamber 1 at an appropriate mixing ratio, and an explosion is caused within the combustion chamber 1 by the spark plug 10. Then, by using the negative pressure suction force generated in the combustion chamber 1 based on the exhaust kinetic inertia of the combustion gas after explosive combustion of the gas-air mixture in the combustion chamber 1, the fuel gas and the combustion air are removed. into the combustion chamber 1 via the backflow prevention valve mechanisms 4 and 6.
By flowing a portion of the exhaust combustion gas back into the combustion chamber 1 from the exhaust passage 9, the gas-air mixture is regenerated using the heat retained in the backflow combustion gas. The explosive combustion cycle of explosive combustion is repeated continuously.

By adjusting the gas flow rate control valve 7, the amount of combustion is changed. It is practically sufficient if the shape of the ventilated tubular air passage 5A of the gas distributor 5 is designed so that the turndown ratio can be up to about 1:5.

Note that the operation of the electric fan 2 and the spark plug 10 is stopped when pulse combustion becomes stable.

The pulse combustion device according to the present invention can be used for various heating purposes, such as heating a fluid by locating a tail pipe constituting the exhaust passage 9 in the fluid, or
It can be used for purposes such as utilizing exhaust energy.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, with FIG. 1 being a schematic vertical sectional view of a pulse combustion device, and FIG. 2 being an enlarged exploded perspective view of the main parts. FIG. 3 is a schematic vertical cross-sectional view for explaining a conventional pulse combustion device. 1... Explosion combustion chamber, 3... Combustion air supply path,
4... Valve mechanism for backflow prevention, 5... Gas distributor, 5A...5 air passageway, 5B...5
gas outlet, 6... backflow prevention valve mechanism, 8...
Fuel gas supply path, 9...exhaust path.

Claims (1)

[Scope of utility model registration request] A gas distributor 5 connected to a fuel gas supply path 8 having a valve mechanism 6 for preventing backflow of explosive combustion gas from the explosion combustion chamber 1 is disposed on the upstream side of the explosion combustion chamber 1, and A combustion air supply path 3 is connected to the upstream side of the gas distributor 5 via a valve mechanism 4 for preventing backflow of explosive combustion gas from the explosion combustion chamber 1, and An exhaust passage 9 is provided on the downstream side of the chamber 1 to exhaust the explosive combustion gas from the explosion combustion chamber 1 by its explosive force, so that the gas-air mixture is discharged from the explosion combustion chamber 1 after the explosion and combustion. Fuel gas and combustion air are caused to flow into the explosion combustion chamber 1 by the suction force due to exhaust kinetic inertia of the combustion gas, and a part of the exhaust combustion gas is caused to flow back into the explosion combustion chamber 1 from the exhaust path 9. This is a pulse combustion device configured to explosively burn the gas-air mixture using the heat retained in the backflow combustion gas, and to continuously repeat the explosion and combustion cycle. Each of the numerous combustion air passages 5A has a tapered shape in which the inner diameter changes continuously so that the inlet side portion becomes smaller in diameter toward the downstream side, and the outlet side portion becomes larger in diameter toward the downstream side. Pulse combustion is formed in such a way that the inner diameter of the passageway 5A is gradually widened, and the fuel gas outlet 5B from the fuel gas supply passage 8 is connected to the vicinity of the minimum diameter part of each of the passage passages 5A. Device.